CSF2 and melanoma: ImlygicTM (talimogene laherparevec, also formerly known as T-VEC), an oncolytic herpes virus expressing granulocyte-macrophage colony-stimulating factor (GM-CSF), was the first OV to gain approval from the U.S. Food and Drug Administration, and European Medicines Agency in 2015, for the loco-regional treatment of melanoma lesions in the skin and lymph nodes [4].